Kate Beckinsale In A Bikini (VIDEO)

01/18/2011 01:08 pm ET | Updated May 25, 2011

Kate Beckinsale showed off blonde hair and a toned bikini body in Mexico with her husband, Len Wiseman, over the weekend.

Kate, 37, starts filming 'Underworld 4' in March so she might have to go back to brunette. What do you think of her new hair color?